Clobazam monotherapy for partial-onset or generalized-onset seizures

There is a need to expand monotherapy options available to a clinician for the treatment of new partial-onset or generalized-onset seizures. A Cochrane systematic review for clobazam monotherapy is expected to define its place in the treatment of new-onset or untreated seizures and highlight gaps in evidence.

To evaluate the efficacy, effectiveness, tolerability and safety of clobazam as monotherapy in people with new-onset partial or generalized seizures.

We searched the following databases: Cochrane Epilepsy Group Specialized Register (5 March 2013), Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, January 2013, Issue 1), MEDLINE (Ovid, 1946 to July 1, 2014), Database of Abstracts of Reviews of Effectiveness (DARE, January 2013, Issue 1), BIOSIS Previews (all years, searched on 5 March 2013). There were no language restrictions.

Randomized or quasi-randomised controlled trials comparing clobazam monotherapy versus placebo or other anti-seizure medication in people with two or more unprovoked seizures or single acute symptomatic seizure requiring short-term continuous anti-seizure medication, were eligible for inclusion.

Primary outcome measure was time on allocated treatment (retention time), reflecting both efficacy and tolerability. Secondary outcomes included short- and long-term effectiveness measures, tolerability, quality of life, and tolerance measures. Two authors independently extracted the data.

We identified two trials fulfilling the review criteria, which included 163 participants. None of the identified studies reported the preselected primary outcome measure. A meta-analysis was not possible. Lack of detail regarding concealment of allocation and a high risk of performance and detection bias in one study prompted us to downgrade the quality of evidence for some of our results due to risk of bias.Regarding retention at 12 months, we detected no evidence of a statistically significant difference between clobazam and carbamazepine (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.61 to 1.12); low quality evidence. There was low quality evidence that clobazam led to better retention compared with phenytoin (RR 1.43, 95% CI 1.08 to 1.90). We could not determine whether participants receiving clobazam were found to be less likely to discontinue it due to adverse effects as compared to phenytoin (RR 0.10, 95% CI 0.01 to 1.65, low quality evidence).

We found no advantage for clobazam over carbamazepine for retention at 12 months in drug-naïve children and a slight advantage of clobazam over phenytoin for retention at six months in adolescents and adults with neurocysticercosis in a single clinical trial each. At present, the available evidence is insufficient to inform clinical practice.